That's all for this. If you feeling missunderstanding, don't worry. There will be special parts about `ioremap` and `fixmaps` in the [Linux Kernel Memory Management](http://0xax.gitbooks.io/linux-insides/content/mm/index.html) chapter.
That's all for this. If you feeling missunderstanding, don't worry. There is special part about `ioremap` and `fixmaps` in the [Linux Kernel Memory Management. Part 2](https://github.com/0xAX/linux-insides/blob/master/mm/linux-mm-2.md) chapter.
Obtaining major and minor numbers for the root device